Begin preparing the ragù from its soul, the soffritto. Keeping them separate, chop the onion, carrot, and celery very finely.
Place a large pot on a small stove and melt butter in olive oil on medium-low flame. Gently sauté the onion for two minutes before adding the carrot, stir, and, after one minute, the celery too.
Combine the salt while stirring. It will help the vegetables pull out their water without burning.
After 3 minutes, or when the soffritto is slightly translucent, add the sweet ground bacon (pancetta), stir, and cook for a few minutes.
Add the ground meat, crumble it with a fork, and stir. When you hear the meat to sizzle, add the wine and let it evaporate. While it evaporates, pour a glass. Is it a good wine? I hope so because you just used it in your meat sauce.
Add tomato sauce and cook for one hour, leaving the pot uncovered and over low heat on a small stove. Bolognese sauce should not boil; it cooks slowly, humming a song under your breath.
After an hour, you are almost halfway through cooking, considering that the first half hour has passed between preparing the soffritto and inserting the other ingredients. It is time to add the milk to the meat sauce. Stir and cook for another hour. But doesn't the meat sauce cook 4 hours? Once, it was necessary to cook the sauce for many hours since the meat was tough. Today, it has more water, and you can reduce the cooking time. I cook the sauce for about 2.30 to 3 hours.
Turn it off and let it cool out; let it stand at least overnight (when cooled, place the pot in the fridge).
The next day, taste and, if necessary, adjust the salt.